Arrays of light emitting elements are known in the art. U.S. Pat. No. 8,985,810, for instance, describes an illumination apparatus and method of manufacture of the same in which an array of light-emitting elements is aligned to an array of optical elements to achieve a thin and efficient light source that can also be arranged to provide directional and/or programmable illumination. Amongst others, this document describes an illumination apparatus, comprising a plurality of light-emitting elements from a monolithic wafer arranged in an array with their original monolithic wafer positions and orientations relative to each other preserved; and a plurality of optical elements arranged in an array; wherein the light-emitting element array is aligned with the optical element array such that the light-emitting elements are aligned with the optical elements; wherein in at least one direction, for at least one pair of the plurality of light-emitting elements in the at least one direction, for each respective pair there was at least one respective light-emitting element in the monolithic wafer that was positioned in the monolithic wafer between the pair of light-emitting elements in the at least one direction and that is not positioned between them in the array of light-emitting elements.
WO 2015/185469 A1 discloses a lighting device which comprises a luminescent concentrator. The luminescent concentrator comprises a waveguide which has a radiation input face, a radiation exit face, and a width which is defined by the radiation input face and an opposite face. The waveguide comprises a radiation converter element which is distributed in the waveguide with a radiation converter concentration. The waveguide comprises a single crystal or a ceramic. A solid state light source is configured to irradiate the radiation input face of the waveguide with solid state light source radiation. The radiation converter element is configured to absorb at least part of the light source radiation and to convert into radiation converter element radiation. The radiation converter concentration is selected at least three times higher than necessary to absorb 98% of the light source radiation over the width of the waveguide.
WO 2015/067476 A1 discloses a light emitting device which comprises a plurality of first solid state light sources which is adapted to, in operation, emit first light with a first spectral distribution. A first light guide comprises a first light input surface, a first end surface extending in an angle different from zero with respect to each other and at least one first further surface extending parallel to the first light input surface. The plurality of first solid state light sources is arranged at the first light input surface. The first light guide is adapted to receive the first light with the first spectral distribution at the first light input surface, and guide at least a part of the first light with the first spectral distribution to the first end surface. The light emitting device further comprises at least one first optical element, which is adapted to shape light that is coupled out of the first light guide through at least a part of the at least one first further surface such as to provide a first shaped light. At least one second optical element is arranged at or on the first end surface.